def is_stupid(n, d):
ndigits = get_digits(n)
ddigits = get_digits(d)
if ndigits[1] == ddigits[0]:
if ddigits[1] != 0:
if Fraction(ndigits[0], ddigits[1]) == Fraction(n, d):
return True
return False
def is_stupid(n, d):
ndigits = get_digits(n)
ddigits = get_digits(d)
if ndigits[1] == ddigits[0]:
if ddigits[1] != 0:
if Fraction(ndigits[0], ddigits[1]) == Fraction(n, d):
return True
return False
def rotations(n):
"Return the set of rotations of the given n. e.g. 37 outputs {37, 73}."
digits = get_digits(n)
result = set()
for i in range(0, len(digits)):
result.add(combine_digits(digits[i:] + digits[0:i]))
return result
def rotations(n):
"Return the set of rotations of the given n. e.g. 37 outputs {37, 73}."
digits = get_digits(n)
result = set()
for i in range(0, len(digits)):
result.add(combine_digits(digits[i:] + digits[0:i]))
return result
def find_curious_numbers():
# Precompute factorials
facts = [factorial(x) for x in range(0, 10)]
# Numbers obeying this rule cannot be larger than 7 digits, because
# 9! * 8 is 2903040, a 7-digit number. (An 8 digit number can never
# produce itself in this way.)
limit = facts[9] * 7 + 1
is_curious = lambda n: sum([facts[x] for x in get_digits(n)]) == n
return filter(is_curious, xrange(10, limit))
def get_permutations(x):
"Return a list of all permutations of digits of x (as integers)."
digits = get_digits(x)
if len(digits) == 1:
return digits
result = []
for i in range(0, len(digits)):
combine = lambda d, e: int("".join(map(str, d)) + "".join(map(str, e)))
result += map(lambda x: x*10 + digits[i],
get_permutations(combine(digits[:i], digits[i+1:])))
return list(set(result)) # Hacky duplicate filter
def get_permutations(x):
"Return a list of all permutations of digits of x (as integers)."
digits = get_digits(x)
if len(digits) == 1:
return digits
result = []
for i in range(0, len(digits)):
combine = lambda d, e: int("".join(map(str, d)) + "".join(map(str, e)))
result += map(lambda x: x * 10 + digits[i],
get_permutations(combine(digits[:i], digits[i + 1:])))
return list(set(result)) # Hacky duplicate filter
def is_palindrome(number):
""" Return true if the number is a palindrome.
Start dividing the number by 10, 100, 1000, etc to get the digits
from the right-hand side of the number.
"""
digits = get_digits(number)
palindrome = True
for (k, v) in zip(digits, reversed(digits)):
if k != v:
palindrome = False
break
return palindrome
def same_digits(numbers):
expect = sorted(get_digits(numbers[0]))
for i in range(1, len(numbers)):
if sorted(get_digits(numbers[i])) != expect:
return False
return True
def is_narcissistic(n, exp):
value = 0
digits = get_digits(n)
for digit in digits:
value += digit**exp
return value == n
#!/usr/bin/env python
"""
A googol (10^100) is a massive number: one followed by one-hundred zeros;
100^100 is almost unimaginably large: one followed by two-hundred zeros.
Despite their size, the sum of the digits in each number is only 1.
Considering natural numbers of the form, a^b, where a, b < 100, what is the
maximum digital sum?
"""
from digits import get_digits
if __name__ == "__main__":
maxsum = 0
for a in range(0, 100):
for b in range(0, 100):
s = sum(get_digits(a ** b))
if s > maxsum:
maxsum = s
maxa = a
maxb = b
print "%d^%d = %d" % (maxa, maxb, maxa ** maxb)
print "Sum: %d" % maxsum
#!/usr/bin/env python
"""
A googol (10^100) is a massive number: one followed by one-hundred zeros;
100^100 is almost unimaginably large: one followed by two-hundred zeros.
Despite their size, the sum of the digits in each number is only 1.
Considering natural numbers of the form, a^b, where a, b < 100, what is the
maximum digital sum?
"""
from digits import get_digits
if __name__ == '__main__':
maxsum = 0
for a in range(0, 100):
for b in range(0, 100):
s = sum(get_digits(a**b))
if s > maxsum:
maxsum = s
maxa = a
maxb = b
print "%d^%d = %d" % (maxa, maxb, maxa**maxb)
print "Sum: %d" % maxsum
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import sys
sys.path.append('../lib')
from digits import get_digits
print sum(reversed(get_digits(2 ** 1000)))
from digits import get_digits
from fractions import Fraction
from itertools import count
def compute_continued_fraction(seq, limit):
"Expand the given continued fration sequence to the nth convergent."
a = seq.next()
if limit == 1:
result = Fraction(a)
else:
result = a + Fraction(1, compute_continued_fraction(seq, limit - 1))
return result
def e_seq():
"The sequence of values given in the problem to compute e."
yield 2
for n in count(2):
if n % 3 == 0:
yield n / 3 * 2
else:
yield 1
if __name__ == '__main__':
result = compute_continued_fraction(e_seq(), 100)
print '100th convergent:', result
print 'Numerator digit sum:', sum(get_digits(result.numerator))
Find the sum of digits in the numerator of the 100th convergent of the
continued fraction for e.
"""
from digits import get_digits
from fractions import Fraction
from itertools import count
def compute_continued_fraction(seq, limit):
"Expand the given continued fration sequence to the nth convergent."
a = seq.next()
if limit == 1:
result = Fraction(a)
else:
result = a + Fraction(1, compute_continued_fraction(seq, limit-1))
return result
def e_seq():
"The sequence of values given in the problem to compute e."
yield 2
for n in count(2):
if n % 3 == 0:
yield n/3 * 2
else:
yield 1
if __name__ == '__main__':
result = compute_continued_fraction(e_seq(), 100)
print '100th convergent:', result
print 'Numerator digit sum:', sum(get_digits(result.numerator))
